1. Field of the Invention
The present invention relates generally to the field of genetics and molecular biology. More particularly, it concerns genetically altered ciliate organisms and the use of such organisms in recombinant protein production.
2. Description of Related Art
Recombinant proteins are useful for a wide range of applications including as industrial enzymes and as therapeutics. For example, production of genetically engineered vaccine antigens, therapeutics (including antibodies and antibody fragments), industrial enzymes, biopolymers, and bioremediation agents now constitute a multibillion dollar-per-year industry. There is also a large market for recombinant proteins in the basic research arena (Pavlou and Reichert (2004); Langer (2005)).
Currently available platforms for the production of recombinant proteins are limited to a relatively small number of cell-based systems that include bacteria, fungi, and insect and mammalian tissue culture cells. Although bacteria can offer high yield and low cost alternatives for production of mammalian proteins, cell culture systems based on higher organisms such as insect cells or mammalian cell systems generally provide proteins having greater fidelity to the natural proteins in terms of protein folding and/or post-translational processing (e.g., glycosylation). Whole transgenic plants and animals have also been harnessed for the production of recombinant proteins, but the long development time from gene to final product can be a major drawback with these multicellular organisms, as can their high cost, low yield and many inherent difficulties in purification.
There remains a need in the art for improved methods for rapid, high-fidelity and cost-effective production and purification of recombinant polypeptides.